Mini BP Booster Clean Boost Effect Full Metal Shell Guitar Pedals True Bypass 1. Internal DIP switches allows you to select the boost frequency and equalization settings. 2. Uses the highest quality parts available with a discrete FET design and low impedance output. 3. Use true mechanical True Bypass switching. 4. Provides up to +20dB of pure boost, and let the tone have a more stereoscopic flare of high and low frequency, and do not produce auditory fatigue. 5. mini size with blue indicator and transparent rotary knob. Internal DIP switches Input Impedance: 1M ohm Output Impedance: 1k ohm Power Supply: 9VDC or 18V (center minus plug)(adapter not included) Color: As Shown Material: Metal+Plastic Package Contents: 1 * BP Booster Guitar Effect Pedal Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.